The oxygen isotope composition of phosphate: a potential tool in UK freshwater studies?

磷酸盐的氧同位素组成：英国淡水研究的潜在工具？

• 批准号: NE/I015361/1
• 负责人: Timothy Heaton
• 金额: $ 6.78万
• 依托单位: British Geological Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI015361%2F1
• 关键词: oxygen; isotope; composition; phosphate; potential

The proposal is for a small, 'pilot' research project to look at the isotopic composition of oxygen atoms in phosphate in river systems. High concentrations of phosphate in rivers and lakes are a primary cause of 'eutrophication': an over-enrichment in nutrients leading to conditions which can result in severe environmental damage (reduced biodiversity, oxygen starvation, fish deaths), health issues (toxic algae), and economic problems (expensive water treatment). Many rivers in the UK, and other parts of the world suffer from this problem because phosphate-rich waters from sewage works or from farming activities are pumped or leak into the rivers. Dealing with this problem involves knowing where the phosphate comes from, and understanding what happens to it when it gets into the river. The phosphate ion consists of a phosphorus atom and four oxygen atoms, and the oxygen atoms can be of different isotope types: oxygen of atomic mass 18 and oxygen of atomic mass 16 (both are naturally-occurring, non-radioactive isotopes). Preliminary studies have shown that the proportions of these two isotopes differ depending on where the phosphate came from (e.g. sewage compared with agricultural fertilizer), and that changes in the proportion of the two isotopes indicates the way in which the phosphate is being used in the water. However, this preliminary work is very limited, and has been mainly done in saline waters in estuaries and coastal areas in other countries. We want to see if it might work in fresh water environments in the UK. The plan is therefore two-fold: 1) to analyse the proportions of oxygen-18 and oxygen-16 in phosphate from a small number of sewage and agricultural effluents, to see if they differ. If they do, we may be able to use measurements of river water to determine where phosphate pollution is coming from. 2) to see if the proportion of oxygen-18 and oxygen-16 in phosphate coming from a particular source (e.g. the outfall of a sewage works into a river) changes as the phosphate is carried downstream. If it does, we may be able to use such measurements to determine the phosphorus demand or 'limitation' of the system - an important factor in controlling eutrophication.

该提议是针对一个小的“试点”研究项目，以研究河流系统中磷酸盐中氧原子的同位素组成。河流和湖泊中高浓度的磷酸盐是“富营养化”的主要原因：养分过度富集导致疾病，这可能导致严重的环境损害（减少生物多样性，氧气饥饿，鱼类死亡），健康问题（有毒藻类）和经济问题（昂贵的水处理）。英国和世界其他地区的许多河流都遇到了这个问题，因为污水处理工厂或农业活动中磷酸盐富含磷酸盐的水域被抽出或渗入河流。解决这个问题涉及了解磷酸盐的来源，并了解它进入河流时会发生什么。磷酸离子由磷原子和四个氧原子组成，氧原子可以具有不同的同位素类型：原子质量18的氧和原子质量16的氧（两者都是自然存在的，非放射性的同位素）。初步研究表明，这两个同位素的比例因磷酸盐的来源而不同（例如，与农业肥料相比，污水与污水相比），并且两个同位素比例的变化表示在水中使用磷酸盐的方式。但是，这项初步工作非常有限，主要是在其他国家的河口和沿海地区的盐水中进行的。我们想看看它是否可以在英国的淡水环境中起作用。因此，该计划是双重的：1）分析磷酸盐中氧气和氧气中的比例与少数污水和农业废水的比例，以查看它们是否有所不同。如果这样做，我们也许可以使用河水的测量来确定磷酸盐污染的来源。 2）查看来自特定来源的氧气-18和氧气-16的比例（例如，污水的排出液在河流中的脱水）是否会随着磷酸盐的下游而变化。如果是这样，我们可能能够使用此类测量来确定系统的磷需求或“限制”，这是控制富营养化的重要因素。